This invention relates to detonating cords. In particular, this invention relates to rugged and safe detonating cords used for reliable detonation of explosive line charges.
Explosive line charges have been used to breach an obstructed area. Usually an interconnected line of distributed explosive charges is pulled across the area by a rocket motor and detonated to clear the obstacles and mines in a narrow lane. Sometimes, detonation and clearing do not always go as planned due to failure in the detonation trains. They fail because line charges are expected to perform under extremely adverse conditions to accomplish difficult missions during combat, and often are subjected to numerous abuses as they are transported to and emplaced in the field. In addition, they must survive intense self-destructive forces as they are deployed by rockets or other highly accelerating launch systems. After launch, impact with the ground, rocks, concertina wire, etc. also may interrupt or otherwise damage the detonation trains. Consequently, detonations are ineffective or interrupted along some of the line charges, and they do not clear paths through obstacles and mines.
Accordingly, an effective man-portable weapon system has been needed that could clear anti-personnel mines and wire obstacles. Contemporary man-portable systems cannot reliably withstand the severe dynamic loading, survive the extreme environmental and logistics conditions, and survive landing over razor sharp wire obstacles like triple standard concertina. None meet all U.S. DOD Insensitive Munition (IM) requirements of MIL-STD-2105 and Naval Systems Command Instruction (NAVSYSCOMINST) 8010.5. The energetic subsystems which include the detonating cords in all previous major weapon systems failed to meet IM requirements, specifically those requirements regarding bullet and fragment impact tests, and slow cook-off tests. In addition, these weapon systems failed to meet the minimum operational requirements associated with mine and wire obstacle breaching during assault. This was because their explosive subsystems (including the detonating cords) led to either: (a) unreliable detonation after exposure to environmental operational conditions, (b) unexpected detonations when exposed to the impact of arms fire as expected during assault breaching operations, or failure to survive landing over razor sharp wire obstacles like triple standard concertina.
In other words, the detonating cords used in some contemporary line charges do not reliably survive deployment via a rocket motor since extreme loads were imposed upon the detonating cord as the line charge flies out of its container at launch and as it impacts the ground during landing. This denied personnel the welcomed operational benefit of being able to emplace and detonate line charges from standoff positions. Use of other industry standard and best commercially available detonating cords fared no better and resulted in repeated failures of the detonating cords. This is because the fast traveling detonating cords could not survive the whip-like acceleration & deceleration environment, as well as the tremendous shearing forces associated with the impact upon razor sharp wire obstacles. Commercial detonating cords have been modified to help survive launch and landing, but physical contraction and expansion cycles over normal temperature and humidity extremes created gaps in the explosive cores at the ends of the detonating cords. This compromises reliability.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for detonating cord that survives the rigors of environment and logistics, severe dynamic loads during deployment, and impact during landing to reliably transfer detonation.